Turbine control apparatus



June 20, 1950 wn- 2,512,021

TURBINE CONTROL APPARATUS Filed Dec. 12, 1945 2 Sheets-Sheet l Fig.1

Ellis E. Hewitt im ATTORNEY June 20, 1950 HEWITT 2,512,021

TURBINE CONTROL APPARATUS Filed Dec. 12, 1945 2 Sheets-Sheet 2 FOQWAQD fig. 6

QEVERSE 1 180 68 72 SELECTION o E 179 fl74 i'76 FULL 15 STEAM 169 177 EEVEESE IAVENTUR Ellis E.H ewiit BY aim Patented June 20, 195( EJN [TED STATES PATENT. OFFICE 5 Claims.

This invention relates to turbine control apparatus and more particularly to apparatus for controlling the supply of motive power to and its out off from a plurality of turbines;

In the copending applicationof Harry 0. May,

Serial No. 550,691, filed August 23', 1944-, now Patent No, 2,501,729, granted March 28, 1950, and" assigned to the assignee of the present application, there is disclosed a; control apparauts for selectively controlling the operation of a forward drive steam turbine and of areverse drive steam turbine of a-locomotive forrailw'ay service; The

A forward throttle valve is'used-for controlling the supply of steam to" and is out off from the forward turbine, and a reverse throttle Valve is employed for controlling the supply of steam to and is out off from the reverse turbine. -An operators control device is operable selectively either to effect operation of the forward throttle valve to supply steam to the forward turbine and at the same time effect operation of the reverse throttlevalve to cut off the supply ofsteam tothe reverse turbine and also effect operation of the clutch to disconnect the reverse turbine from the locomotive drive wheels, or to effect operation of the forward throttlev'alve to cutoff the supply of steam to the forward turbine and at the same time eifectoperation of the clutch to connect the reverse turbine to the drive wheels and also effect operation of the reverse throttle valve to supply steam to drive the reverse turbine.

Provision is-made in the above described apparatus to cause full closing oi -both the forward and reverse throttle valves for cutting off the supply of steam to the respective turbines, when such is desiredJout particularly where the throttle valves are of the poppet type they may be un desirably held open to a greater or less degree by foreign matter, such as a piece of pipe scale on the seat, in which event leakage of steam to the respective turbine" will occur at a time when it is desired that no steam be supplied to the turbine. Slight leakage of steam to the forward turbine is however not too detrimental, but leakage to the reverse turbine is objectionable for itwill tend to cause continuous and unnecessary rotation of the reverse turbine rotor when dis connected from theidrive wheels, and if such leakage is sufficient said-rotor might evenbe caused to spin at such a" speed as to damage the turbine. Still further, if the operator desired toprop'el the locomotive rearwardly and engaged reverse turbine was turning under the influence of steam leaking through the reverse throttle valve, the clutch and even the turbine or other parts of the locomotive might be severely damaged.

The principal object of the present invention is, therefore, the provision of means for insuring that steam-will-not be sup-pliedto the reverse turbine when not desired;-

Other objects and advantageswill be apparent from the following more'detaileddescription of the invention.

In the accompanying drawings; Fig. 1 is a diagrammatic view, partly section and partly 2'o -in outline; ofa control apparatus embodying the invention; Fig. 2-=is a partial plan view of an operatorscontrol device in section in Fig.

1; Figs. 3;, 4 and 5 are sectional views taken on lines 3---3-,4*-4w, and 5=--5 on the operators con- 25 trol-devicein-Fig; I;- and Fig 6 is a vertical crosssectional view of an interlock valve device shown in side elevation in Fig '1.

Description In the drawings, the reference numeral l indicates' a drive axle of a rail locomotive. A reduction gear housing 2' is mounted. on axle I and contains a driving gear wheel 3- secured to the axle l' for turning same. The gear wheel 3 is arranged to be operated by a smaller gear wheel 4 mounted on-a jack-shaft 5 which is journaled in the housing 2. The shaft 5' is arranged to be driven by gear wheels '6' which mesh with smaller driving gear wheels- '|:mount-e'd on and arranged to be driven by a shaft 8 having: bearings in the housing. 2' and extending out from either side thereof.

One end of shaft '8 is permanently connected to a forward: steam turbine 9 which is arranged to be operated by steam-supplied through a pipe It for driving axle I to propel the locomotive in a forward direction. Numeral H indicates anexhaust pipe from the turbine 9.

A reverse turbine 12 arranged to be operated by steam supplied through a pipe l3: and: having a steam exhaust pipe [4 is adapted to drive a shaft L5: The shaft 15 extends into a reduction gear housing It containing meshing gear wheels I! and +8, the gear wheel l'l being secured to 55 sa idshaft and the sear wheel 18 being secured the reverse turbineol'utch when the rotor in the amber to a shaft l9 which is journaled in said housing in coaxial relation with shaft 8 connected to the forward turbine 9. A fixed clutch element 23 is rigidly secured to shaft 8 to rotate therewith, and slidably mounted on the adjacent end of shaft I9 is a movable clutch element 2| arranged to cooperate with the fixed clutch element 23 to operatively connect the reverse turbine l2 to the shaft 8 for driving the axle I.

It will be noted that the forward turbine 9 is at all times connected to the locomotive axle I while the reverse turbine may be either connected or disconnected by the clutch 2|], 2|. Thus fully disclosed in the copending application hereinbefore referred to, but with a view to simplicity in the present application, each of said motors may comprise, for illustrative purposes only, a

when the reverse turbine l2 is employed for driving the locomotive the rotor (not shown) of the forward turbine will also be operated, but the clutch 25, 2| provides for discormecting the reverse turbine |2 from the drive shaft 8 when the engine is being driven by the forward turbine 9.

For operating the clutch element 2| to connect and disconnect the reverse turbine l2 to and from the drive shaft .8 there is provided a fluid pressure controlled motor comprising a cylinder 22 containing a piston 23 which is operatively connected through a rod 24 to one end of a lever 25. This lever is arranged to rock about a fixed fulcrum 26 provided intermediate its ends. The opposite end of lever is in the form of a yoke straddling the movable clutch element 2| and has operating engagement therewith within an annular groove 2'1. At one side of piston 23 is a pressure chamber 28 which is arranged to receive fluid under pressure from a clutch control pipe 29 for actuating said pistonto rock the lever 25 in a clockwise direction to urge the movable clutch element 2| into driving engagement with the fixed clutch element 20 to thereby operatively connect the reverse turbine l2 to the drive shaft 8. At the opposite side of piston 23 is a non-pressure chamber containing a spring 30 which functions to move the piston 23 to the position in which it is shown in the drawing upon release of fluid under pressure from pipe 29 and chamber 28 for disengag ing the movable clutch element 2| from the fixed clutch element 20 tothereby disconnect the reverse turbine I2 from the drive shaft 8.

The reference numeral 3| indicates a steam supply pipe for conveying steam from the locomotive boiler (not shown) to a forward steam throttle valve 32 and a reverse steam throttle valve 33 which are provided for controlling or regulating the steam supply to respectively, the forward and reverse turbines 9 and I2.

The reverse steam throttle valve 33 may comprise a casing having a chamber 34 open to the steam supply pipe 3| and containing a poppet valve 35 for controlling flow of steam from said chamber to a chamber 36 which is connected to pipe [3. The valve 35 has an operating stem 3'! extending to the exterior of the casing. The valve 35 is shown in the closed position for preventing supply of steam to pipe l3 and thus to the reverse turbine l2 and is constantly urged toward this position by the pressure of supply steam in chamber 34. By operating stem 31 the valve 35 may be unseated to supply steam from pipe 3| to the reverse turbine l2, it being apparent that the amount of steam supplied to said turbine may be varied inaccordance with the degree of opening or unseating of said valve.

The forward throttle valve 32 for regulating the supply of steam from the supply pipe 3| to pipe 10 and thence to the forward turbine 9 casing 40 containing a piston 4| having at one side a pressure chamber 42 and at the opposite side a pressure chamber 43. The piston 4| is provided with a rod 44 extending through chamber 43 and a bore in a cover 45 which closes one end of said chamber. A packing 46 in cover 45 engages the peripheral surface of rod 44 for preventing leakage of fluid under pressure from chamber 43 along said rod to atmosphere.

The piston rod 44 is arranged at right angles to the axis to the respective poppet valve stem 3'! and is connected to a cam member 53 havin on one side an inclined surface 41 for en-- gaging the end of said stem to unseat the valve iii upon movement of piston 4| in the direction of the left hand, as viewed in the drawing. This inclined surface is so arranged that when piston 4| is at the right hand end of the casing, as shown in the drawing, the valve 35 will be seated and the degree of opening of said valve by the inclined surface is so arranged that when piston steam supplied from the steam supply pipe 31 to the respective turbine 9 or l2, will vary according to the extent of movement of said piston from said position in the direction of the left hand. When chamber 43 is open to atmosphere, piston 4| is adapted to be moved against the opposing pressure of a spring 48 by fluid under pressure supplied to chamber 4iv in a manner which will be later described, for opening the respective poppet valve 35, while upon release of fluid under pressure from chamber 42 spring 48 is adapted to move said piston to the position shown in the drawing to permit poppet valve 35 may become fully seated to prevent leakage of steam to the respective turbine 9 or l2. The cam member 53 may alsohave a surface 41a. parallel to the surface 4?, and the end of the valve stem 31 may be in the form of a stirrup having a portion 54 disposed below said member for engagement by surface 41a to move valve 35 from a fully open or substantially fully open position toward its closed position upon movement of piston 4| by spring 48. When the supply valve 35 is closed and piston 4| is in the position in which it is shown in Fig. 1 of the drawing there will be clearance between surface 41a and the portion 54 of the stirrup in accordance with conventional practice.

In the forward throttle adjusting motor 38 chamber 42 is connected to a forward speed control pipe 49 and chamber 43 is connected to a pipe 50, while in the reverse throttle adjusting motor 39 chamber 42 is connected to a reverse speed control pipe 5| and chamber 43 is connected to a pipe 52.

Selective control of the forward and reverse throttle adjusting motors 38 and 39, and thereby selective control of the supply of steam to the forward and reverse turbines 9 and I2, respectively, in accordance with the desired direction.

of movement of the locomotive, is arranged to be controlled by an operators'control valve device 55.

The operators control device 55 comprises a body portion to which is mounted "on one face of a pipe bracket 51', a throttle adjusting motor selector valve portion 58 mounted on another: face of said bracket, and a cover 59 mounted onthe body portion 56.

The body portion 55 carries ahollow rock shaft 60 suitably journaled at opposite ends and secured against longitudinal movement, mounted to slide within said rock shaft longitudinally thereof is a plunger Bl. Adjacent one end, the rock shaft 69 is provided through one side with a slot, and the plunger 6! has a through -.forward at the remote end of the portion 68 slot which is in alignment with the slot in the shaft 69, and extending through said slot in the rock shaft and into said slot in said plunger is an end portion-62 of-an operator's control lever 63. The rock shaft 60 is provided at either side of its slot with spaced upstanding ears 64 between which the portion 62 of the operators control' lever is disposed. Extending through the ears 64 and through the interposed portion of control lever 63 is a pivot pin 65 for said lever, said pin being arranged at right angles to the axis of the rock shaft 60. In the inner end of the portion 52 of the operator s control lever is a recess in which is disposed a pin 66 which is secured to plunger- 6|. Bythis structure it will be seen that movement of the-operators control lever 63 about pin 65 in the direction of the length of rock shaft 69 will move the plunger 9| longitudinally in said shaft, while movement of said lever in a direction circumferentially of said shaft will turn said shaft and plunger in unison.

The cover 59 is provided with a slot through which the operators control lever 63 extends and which is adapted to define a path of movement for said lever. This slot comprises a central porselection position at the junction of the portions 61 and 68 of the slot and then to a stop position, a slight distance into the portion 68 of the slot from the forward selection position. At

the opposite or outer end of the portion 68 of the slot, the lever 61 has a full steam position, the range of movement of said lever between the stop position and the full steam position constituting a speed control range or zone for varying the supply of steam to the forward turbine 9 from, respectively, a minimum amount to a maximum amount in a manner which will be later described. The minimum amount just mentioned is less than required to cause operation of the forward turbine 9 to propel the locomotive and is substantially equal to the steam slip in the turbine so as to maintain the turbine warm when the locomotive is stopped in order and that said turbine will be condition to operate efficiently when required for propulsion.

The lever 63 has at the opposite end of the portion 61 of the slot a reverse selection posi- 1 tionand in the portion 69 of the slot stop and fullsteampositions for controlling the reverse; turbine l2,.the space between said stop and fullsteam positions constituting a speed varying range for said turbine, and the stop =fposition also providing for supply of steam to the the slot all steam to the turbines is adapted to l l5;be cut off, as will be described in greater de-- tail, hereinafter.

These different positions of lever 63 are indicated in Fig. 2 of the drawings by appropriate legends,.and there are also shown the legend 'of the slot and the legend reverse at the opposite end of the portion 69 of the slot, the last two mentioned legends indicating the directions of movement of lever 63 from neutral position -for obtaining ahead or reverse operation of the tioned where it is connected to a hand grip '19 provided for the operator to take hold of to move said lever to its different positions.

Associated with the body portion 59 of the operators control valve device is a reverse steam ;cut off valve device H and'a forward steam out off valve device 12.

The reverse steam cut ofi valve device ll comprises a supply valve 13 contained in a chamber a 14 and connected by a stem 15 to a'plunger T6 i slidably mounted in a suitable bore in the casing. The casing has an annular recess encircling the plunger 16 and containing a sealing" ring 11 for preventing leakage of fluid under presi sure from a chamber 18 to a chamber 19, the

latter chamber being open to atmosphere through ing for engagement by valve 13.

in chamber"! acts on the supply valve 173 for a port 80. A wall 82 separates chamber M from chamber 18 and the stem 75 loosely extends through an opening in said wall which in chamber 14 is provided with a seat around said open- .urging it into contact with its seat. The supply valve 13, stem 15 and plunger 16 are provided with an axial bore which is open at one end to chamber 14 and which is open through a valve seat at the opposite end to chamber 19 which contains a release valve 94 arranged to cooperate with said seat for controlling release of fluid under pressure from chamber 14 to chamber 0. 19. The release valve 84 is carried by a stem 85 The cam at is so designed as to effect movement trol lever is in any. position between and inwhich is disposed directly below the axis of rock shaft 60.

The rock shaft til is provided with a cam 35 arranged to contact the release valve stem $5.

of valve 84 into contact with its seat and to then act through plunger it and stem is to: move the supply valve 13 out of engagement with its seat, when the operators control lever 63 is disposed in the portions 6! and 68 of the slot, and to permit closing of said supply valve by spring 83 and opening of the release valve 84 by pressure of fluid from chamber J4 when the operators con- A spring 83 7 eluding stop and full steam positions in the Portion 690i the slot. a J

Chamber" is arranged to be constantly supplied with fluid under pressure from a fluid pres sure supply pipe 81 'while the locomotive is in use. Chamber 14 is connected to pipe 52 which leads to spring chamber 43 in'the'reverse throttle adjusting motor 39. It willthus be seen that when the operators control lever 83 is in any position between and including the stop and full steam positions in the portion 69 of the slot, which provides for control'of the reverse throttle adjusting motor 39 me manner which'will be later described, the spring chamber43 in said motor will be open to atmosphere past the release valve 84 to provide for operation of said motor by fluid under pressure supplied to chamber42 for controlling the steam supply to the reverse turbine i2, while in all positions of said lever, fluid under pressure will be supplied to spring cham-- ber 43 in the'reverse throttle adjusting motor 39 to cause operation thereof to permitclosing of valve 35 in the reverse throttle valve 33 to cut oif the supply of steam to the reverse turbine.

The forward steam cut-off valve device I2 is structurally identical to the reverse steam cut-off valve device H and, briefly, comprises a supply valve 90 contained in a chamber 9| which is connected to pipe 59 leading to spring chamber 43 in the forward throttle adjusting motor 38. The valve 99 is arranged to control supply of fluid under pressure from a chamber 92 to chamber 9I, the chamber 92 being constantly supplied with fluid under pressure from the supply pipe 81. The forward steam cut-off valve device further comprises a release valve 93 and an operating stem 94 arranged to cooperate with a cam 95 on the rock shaft 60. The cam 95 is formed just the reverse of cam 96 so that with the operator's con- I trol lever 63 in the forward speed control zone, that is to say, in and between the stop and full steam positions in the portion 88 of the slot, the spring chamber 43 in the forward throttle adjusting motor 38 will be open to atmosphere past the release valve 93 to provide for adjustment of said motor by pressure of fluid in chamber 42, while in all other positions of the operators control lever the forward steam cut-off valve device I2 will act to supply fluid under pressure to spring chamber 43 in the forward throttle adjusting motor 38 to insure operation thereof to permit closing of the steam supply valve 35 in the forward throttle valve 32 to cut off the supply of steam to the forward turbine 9.

The forward and reverse cut-off valve devices H and 12 will thus act to insure operation of the forward and reverse throttle adjusting motors 38 and 39 to permit closing of the respective steam supply valves 35 for cutting off the supply of steam to the turbines when the controlling lever. is in the central portion 61 of the slot, and will insure operation of the reverse throttle adjusting, motor 39 to permit closing of the respective throttle valve 35 when the operator's control lever is positioned for supplying steam to the forward turbine 9, and will also insure operation of the forward throttle adjusting motor 38 to permit closing of the respective throttle valve 35 when the operators control lever is positioned for supplying steam to the reverse turbine.

The throttle adjusting motor selector valve portion 53 of the operators control valve device 55 comprises a forward selector valve device 91 for controlling communication between pipe 49 from the forward throttle adjusting motor 38 and a 8 l I passage 98, and also comprises a reverse selector valve device 99 for. controlling communication between said passage and pipe 5| leading to the reverse throttle adjusting motor 39. The passage 98 leads to a self-lapping speed control valve device [lit also forming a part of the operators control valve device 55.

The forward selector valve device 91 comprises a plunger IGI slidably mounted in a suitable bore in the casing and having at one side a chamber 102 which is open to atmosphere through a passage I93, a chamber I94 and an insect excluding device [95. The plunger lill is connected bya stem I38 to a fluid pressure supply valve lllI which is contained in a chamber I98, said stem extending through an opening in a wall I09 separating said chambers. I99 is provided with a seat which extends around the opening therein for engagement by the supply valve I9I. A spring H9 in chamber I08 acts on the valve I91 for urging said valve to its closed position in which it is shown in'the drawing.-

The valve till, stem I96 and plunger IBI are provided with an axial bore Ill open at one end to chamber I98 and open at the opposite end to chamber I92. In chamber I32 the plunger IUI is provided with a seat which extends around the bore ill for engagement by a release valve H2 contained in said chamber. Located above the release valve [i2 is a plunger I I3 which is slidably mounted in the casing in coaxial relation with said valve and with plunger WI. The plunger I I3 is subject on its lower face to pressure of fluid in chamber 92 plus the pressure of a spring I I4, and is open at its upper face to a, chamber H5.

When fluid under pressure is supplied to chamber H3, in a manner which will be later described, the plunger H3 will move against the oppo;-:ing force of spring H4 to first seat the release valve ii'2 against the plunger I9! for closing communication between chamber I82 and chamber 298. Further movement of plunger H3 by fluid pressure in chamber H5 will then act through the release valve H2 and plunger IllI to unseat the supply valve N11 for opening communication between passage 98 and chamber I08 which is connected.- through pipe 99 to piston chamber 32 in the forward throttle adjusting motor 38. Upon release of fluid under pressure from chamber H5 spring H4 will return plunger M3 to the position in which it is shown in the drawing to allow closing of the supply valve llJ'I by spring H9 and opening of the release valve H2 by pressure of, fluid in bore H I for connecting chamber H18 and thereby chamber 42 in the forward throttle adjusting motor 38 to atmosphere.

The reverse throttle selector valve device 99 is structurally identical to the forward throttle se- .iector valve device 91 and briefly, comprises a supply valve I 16 for controlling flow of fluid under pressure from passage 98 to a chamber H8 which is connected to pipe 5| leading to chamber 32 in the reverse throttle adjusting motor 39.

The reverse throttle selector valve device 99 further comprises a release valve H9, contained in chamber (84, for releasing fluid under pressure from chamber 42 in the reverse throttle adjusting motor. The device also comprises a plunger I29 arranged to operate in response to supply of fluid under pressure to a chamber I2! to close the release valve ll 9 and to open the supply valve H9. Upon release of fluid under pressure from chamber I 2! a spring'l22'will return plunger I29 'to'the position in which it is shown in' the draw In chamber I08 the wall ing to permit closing of the supply valve H6 by a spring I23 and opening of the release valve I I9 by pressure of fluid from chamber H8, so as to thereby open pipe i and'pressure chamber 42- in the reverse. throttle adjusting motori39 to atmosphere.

The plunger chamber H5 in the forward selector valve. device 9.1 is connected to a passage I24, and the plunger chamber I2I in the reverse selector device 99 is. connected to a passage I25. The passages I2 i and I215 lead respectively to forward and reverse directional control valve devices I25 and I2? provided in. a, direction selector portion Hi8v of the operators control valve device 55.

The forward directional control valve device I25 comprises a plunger I29 slidably mounted in a bore in the casing and connected by a stem I! to a supply valve. I 3i contained in a chamber I32. The stem 130. extends through a chamber its form-edat one side of plunger I29 and also througha bore provided in a wall I34 which separates said chamber from chamber I32, said Wall being provided around said bore in chamber 32 with a seat for engagement by the valve I3I. A spring I35 in chamber I32 acts on the supply valve for urging it to its seat. The supply valve 53!, stem 53% and plunger I29 are provided with an axial bore open at one end to chamber I32 and open at the opposite end through a valve seat to. a chamber I36 which is open to atmosphere through a. port I38. A release valve I39 contained in chamber I36 is provided to engage a seat on the. end of plunger I29 for closing communication through the bore in said plunger. Chamber I33 is open. to the fluid pressure supply pipe 3! and. thus adapted to be constantly supplied with fluid under pressure. Chamber I32 is connected to passage I24 leading to plunger chamber I I5 in the forward throttle selector valve device 81. The release valve I39 is provided with a stem It I. whic-his slidably mounted in the casing and which extends beyond an exterior sur face thereof.

The reverse directional control valve device I 21 is structurally identical to the forward directional control valve device I26 and, briefly; comprises a supply valve M3 contained in a chamber IM andwhich is arranged to be seated by the pressure of a spring I 45. The supply valve IMI is connected by a Stem I46 extending through a chamber I42 to a plunger Ml at the outer face of which is a chamber I48 which is open to atmosphere through a port M9. A release valve 55B. contained in chamber I43 isv arranged to ccof plunger It? for controlling release of fluid under pressure from. chamber I44 to atmosphere by of chamber I48. The release valve I59 has a. stem I51 extending through a. bore in the casing and beyond an exterior surface thereof. Thechamber i42- isadapted to be constantly supplied. with fluid under pressure from the fluid pressure supply. pipe 8.? through chamber I33 and a passage Mt" Chamber IM- isconnected to'pas- 52 5. leading to. plunger chamber I2I in the reverse throttle selector valve device 99.

The two. release valve stems I51 and. t ll are arranged in spaced parallel relation with respect to each other and to the axis of plungerti which is mounted. to slideinthe roclr shaft til. The release valve stem l t-I is engaged by one end of a lever 9 5.2 which substantially midway between its ends. is iulcrumed onra pin I53. mounted on a bracket I54. projecting from the casing of the operate with aseat rovided-on the adjacent end device. The opposite end of lever I52 is disposed in a recess I55 provided in plunger SI, so that longitudinal movement of said plunger will rock the lever I52 about the fulcrum pin I53. The release valve stem I5I is engaged by a lever I56 substantially midway of its length. One end of lever I56 is fulcrumed on a pin It! provided in a bracket I58 projecting from the casing, while the opposite end is disposed in a recess I59 provided in plunger 6|, so as to move with said plunger upon longitudinal movement thereof.

With the operators control lever 63in neutral -position, as shown in" Figs. 1 and 2 of the drawings, the levers I52 and I56 will be positioned to permit opening of the release valves 639 and I and closing of the supply valve I3I and I53 so as to thereby release fluid under pressure from plunger chambers I15 and MI in the forward and reverse throttle selector valve devices 91 and 99, respectively. The release valves H2 and II9 in the latter devices will therefore be open and the supply valves it? and IItwill be closed, so that piston chambers 42 in the forward and reverse throttle adjustingmotors 38 and 39, respectively, will be open to atmosphere. Thus with the operators control lever 53 in neutral position, pistons ll" in the forward and reverse throttle adjusting motors 3% and 39 will bepositioned by springs 58 as shown in the drawing to permit closing of poppet valves 35 in the forward and reverse throttle valves 32 andtt for cutting off supplyof steam to-the forward and-reverse turblues t and I2, respectively.

The operators control lever 63 when moved to the position designated by the legend forward selection in Fig. 2' will move plunger t I- longitudinaily in the direction of theleft hand (Fig. l) to thereby actuate lever I52 to close the release valve I39 and open the supply valve Itl in the forward directional control valve device I25. Thus in this position of the operators control lever fiuid under pressure willbe supplied from the supply pipe 8-1 to passage IN and thence to plunger chamber H5 in the forward throttle selector valve device 91 to thereby actuate said device. to establish communication: between passage 93 and pipe 9 leading to the forward throttle control motor 33. In this forward selection position ofv the operators control. lever I33 it will be noted that the parts of the reverse directional control valve device I2l will remain in the positions in which they are shown in Fig. l for opening. plunger chamber I25 in the reverse throttle selector valve device v99 to atmosphere, so. that the latter device will remain in the. condition opening to atmosphere pipe leading to the reverse throttle adjusting motor in order that said motor will be conditionedto permitcu'tting off of the supply of that legend reverse selection in Fig. 3, the

plunger SI will be moved longitudinally in the direction of the right hand to actuate lever I56 for closing release valve I56 andopening the supply valve I l-il in the reverse directional control valve device I21, while allowing the parts of the forward directional control valve device I26 to remain in the positions in which they are shown in Fig. 1. As a result, fluid under pressure will be supplied from passage I46 to passage I25 and thence to plunger chamber I 2I in the reverse throttle selector valve device 99 for operating said device to open communication between pipe 98 and pipe 5! leading to the reverse throttle adjusting motor 39. Under this condition the parts of the forward throttle selector valve device 9'! will remain in the position in which they are shown in the drawings for opening pipe 49 and thereby chamber 42 in the forward throttle adjusting motor 38 to atmosphere. This condition of the forward and reverse directional control devices I 26 and I2'Iwill be maintained as long as the operators control lever 63 is at the left hand side of neutral position, as viewed in Fig. 2, and therefore during adjustment of said lever in the portion 69 of the guide slot.

The self-lapping valve device I60 may be of any suitable type arranged to supply fluid at various degrees of pressure from a chosen minimum pressure to a certain maximum degree. For illustration, the self-lapping valve device may be of the type comprising a control plunger I69 and valve means (not shown) controlled by longitudinal movement of said plunger for providing in passage 98 fluid at a pressure proportional to the degree of movement or displacement of said plunger from a normal position in which it is shown in Fig. l of the drawing, and operable in said normal position to reduce the pressure of fluid in passage 98 to a chosen minimum degree such as atmospheric pressure. Fluid under pressure for supply to passage 98 by operation of the self-lapping valve device I66 is provided through the fluid pressure supply pipe 81.

For controlling displacement of plunger I60 from its normal position, the rock shaft 6!) is provided with a cam I 6| having two identical but reversely arranged and spaced apart cam portions I62 and I63 on the peripheral surface of the cam. The peripheral surface of the cam is operatively connected to plunger I60 through a ball like end I64 of an arm I65 the opposite end of which is mounted to rock on a pin I66 provided in the casing.

With the operators control lever 63 in neutral position and in both the forward selection and reverse selection positions, the cam I (H provides for movement of the plunger I60 to its outermost or normal position in which the selflapping valve device I90 will operate to open passage 98 to atmosphere. Movement of the operators control lever to either stop position is adapted to cause operation of cam I6l to effect operation of the self-lapping valve device IEO to supply fluid at a chosen pressure, such as pounds, to passage 98, which pressure effective in piston chamber 42 of the forward or reverse throttle adjusting motor 38 or 39. as the case may be and as will be later described, will actuate said motor and thereby the respective throttle valve 32 or 33 to supply the hereinbefore mentioned minimum amount of steam to the respective turbine 9 or I2.

The operators control lever 63 when moved in the portion 68 of the slot from "stop position to the full steam position will cause operation of cam IN to effect displacement of plunger 469 into the self-lapping valve device I90 an amount proportional to the extent of movement away from stop position to thereby provide in passage 68 fluid at a proportional pressur A maximum pressure of fluid such as 65 pounds will be obtained in passage 93 upon movement of the operators control lever in portion 68 of the slot to the full steam position. Adjustment of the operator's control lever in the reverse direction in the portion 68 of the slot will cause the pressure in passage 98 to reduce in proportion to the distance the lever is out of the stop position, while return of said lever to the forward selection" position will cause operation of the self-lapping valve device I 00 to reduce the pressure of fluid in passage 68 to atmospheric pressure as above mentioned.

In a like manner the pressure of fluid in passage 98 will be varied in accordance with adjustment of the operators control lever 63 in the portion 69 of the slot, as will be apparent.

The overall operation of the apparatus as so far described will now be set forth.

Let it be initially assumed that the operators control lever I3! is in neutral position effecting operation'of the forward and reverse directional control valve devices 126 and I2! to open the plunger chambers H5 and I2I in the forward and reverse throttle selector valve devices 91 and 99 to atmosphere. The forward and reverse throttle selector valve devices 91 and 99 will thus be "conditioned to open pipes 49 and SI and thereby piston chambers 42 in the forward and reverse throttle adjusting motors 3B and 36 to atmosphere to permit movement of the throttle adjusting pistons 4| by springs 48 to their steam cut off position to permit closing of the steam supply valves 35 in the forward and reverse throttle valves 32 and33 for preventing supply of steam to the forward and reverse turbines 9 and I2, so that the locomotive may be stopped.

Further, with the operators control lever 63 in neutral position the forward and reverse steam cut-off valve devices 72 and II will be conditioned for supplying fluid under pressure to pipes 56 and 52 leading to spring chambers 43 in the forward and reverse throttle adjusting motors 38 and 39, respectively, to insure that pistons 4| in said motors will be occupying their steam cut-off positions, as shown in Fig. l of the drawing.

Moreover, with the parts of the reverse directional control valve device I21 in the positions in which they are shown in the drawings pressure chamber 28 in the clutch control cylinder 22 will be open to atmosphere through pipe 29 and passage I25 to permit movement of piston 23 by spring 39 to disengage the movable element 2! of the clutch from the fixed element 26 so as to disconnect the reverse turbine i2 from the forward turbine drive shaft 8.

Now let it be assumed that forward movement of the locomotive is desired. To accomplish this the operator will move lever 63 from neutral position first to the forward selection position to thereby actuate the forward directional control valve device I26 to supply fluid under pressure to passage I24 and thence to plunger chamber I I5 to operate the forward throttle selector valve device 91 to open communication between passage 98 from the self-lapping valve device I60 and pipe 49 leading to the forward throttle control motor 33. The operator will then move the control lever 63 from the forward selection" position to stop position in the portion 68 of the slot to actuate the forward steam cut-off valve device I2 to release fluid under pressure from spring chamber 43 in the forward throttle adjusting motor 38. In the stop position just piston chamber 4% in the forward throttle control motor 39 at the pressure, such as pounds, sumcient to cause operation of said motor and thereby ofthe forwardthrottle valve 32 to supply steam to the forward turbine 9 in an amount insufficient to cause operation of saidturbine but which will provide for heating thereof as hereinbefore described.

Movement of lever 53 past stop position in the direction of full steam position in portion 68 5 of the slot will then cause operation of the self-lapping valve device lilll and thereby of the forward'throttle adjusting motor 38 and throttle valve 32 to increase the supply of steam to the forward turbine 9 in an amount proportional to the distance the lever isaway from said stop position, to thereby cause operationof the forwardturbineto turn the locomotive axle --I and drive the locomotive in-a forward direction. By proper adjustment of lever 63 'in' the-portion 68 of the slot any desired amount of steam-may be supplied to the forwardturbine 9 as will'be apparent .from the above description. Return of lever-i3 .to-stop position in the portion 68 of the slot willreduce the supply ofsteamtothe forward turbine to-the minimum amountwhich is insufiicient for causing operation of the turbine as before mentioned.

It will-thus be seen that by suitableadjustment ofthe operators control lever in the portion 58 of the slot between'the stop and fullsteam positions any desired'degreeof speed or output of' power for the turbine may be obtained for propelling the locomotive in a forward direction, itbeing noted that during this operation of the forwardturbine-Si incident to the operators controllever being at the forward selection side of neutral position-the reverseturbine I2 is non-operaitve and disconnected from-the locomotive--axle since the reverse directional control valve device 827', the reverse throttle selector valve device 99; the reversesteam cut-off'valve device H and thereby the reverse throttle adjusting motor 39 remain inthe positions in which they are shown in the drawings.

Inv order to stop thelocomotive-from.move-- ment in the forward:direction, the operator need only returnlever $3 to stop positioni adjacent forward selection position'to cutioff the supply of: propellingsteamto the forward turbine :Qyas willbe apparent.

If the operator now desires to move the locomotivein th reverse :directionthe .will move the control lever '63 to the reverse selection position for operating the reverse directional-control valve device l2! to supply fluid under pressure to passage E25 and thence to plunger chamber l2! in the reverse throttle selector valve device 99 for: actuatingthe latter device to: connect pipe 5! from the reverse throttle adjusting motor 39 to passage .98 leadingto the speed control valve device-.188; Fluid under pressure supplied to passage 25 will also flow through pipe 29 to the clutch control cylinder??? to actuate piston '23 therein. to move clutch element 2!. into "driving engagement with the element 2?] for connecting the reverse turbine !2 to drive shaft 8.; The operator will then move lever !63 from the freverse selection position to stop position in the portion es of the guide slot and this movement will efiect operationof the reverse steam cut-off to :propel the locomotive inreverse.

valve device I! t to: open spring chamber 43 m the reverse a throttle adjusting motor 39 to atmosphere and at thesame time will cause operation ofitheself-lapping valve devicev I09 to supply ii'uid to passage 98 and thence through the reverse throttleiselector-valve. device 99110 piston chamber 421m the reverse throttle-adjusting motor 39* at a. pressure to causeoperation of said motor and therebyof the throttle valve 33' to supply steam tOluthGlGVEI'SG turbine 12 in an amount insuflicient to cause operationof said turbine-but suflicient for heatingsame; as before described. Suitable adjustment oflever 63 in the portion 69 of the slot between the stop and .full steam positionswill'then cause operation of the reverse throttle adjusting motor 39 and reverse throttle valve .33 to supply any chosen'amount of steam to. the IeV6ISe:tllIbill8 I2. When desired, the locomotive may be stopped by returning theoperiators"controllever63 to the stop. position for rendering the reverse turbine non-operative, as will .be apparent from .theprevious description.

Return of the operators control lever 63 to neutral position will effect operationofthe dierectional control valve device I2 7: to open pipe lzii'to atmosphere to'permitrelease' of fluidunder pressure from piston chamber .28in the clutch controlcylinder 22 to render spring '3flz'effective to'disengagez the clutch elements 2| and .20",:and at the same time wil'llefiect operation of the re- Eiland. thereby piston chamber 42 in the reverse tlnottleadjusting motor-39 to atmosphere; Also, in neutral position the reverse "steam cut-01f valve device H will be operated to supply fluid under pressure to spring chamber:in:the-reverse throttle adjusting motor .39. to insure movement of'thepiston-4 l: therein to the steam cut-off position'twpermit full-closingof the steam supply valve 9'5 in the reverse throttle valve 33 for cutting oil the supply of steam: to the reverse turbine I21 I It isdesired to :pointout that when the operators control lever is at the reverse selection :sideof neutral position, the parts of the forward directional control'valvedevi'ce -|'2'$,':the forwardsteam: cut-off" valve device T2 ,:'the' forward throttle selector valvedevice' 91: and the forward throttle adjustingzjmotor- 3851Wi-1I remain. in the positions in which they are shown :in the drawings for :renderingrtheforward turbine 9 non-@operativeduring operation of the reverse turbine [2 However, since-:the forward turbine.- 9 at all times conneetede tothe locomotive axle: I, its rotor (not shown) willturn: as the locomotive is driven by the reverse turbine; l2, as hereinbefore mentioned.

The structure so far described is substantially thew-same as structure "fully' disclosed and described-inathe- 'copendirig application .hereinberore !lrpet: fvalve of the vreverse':throttlexdevice 33 .so

as' to prevent steam being supplied to the reverse -turbine. ,On the other hand, when the reverse rturbhie I2 is driving the locomotive through the clutch 2B, 2!, fluid under pressure is supplied to spring chamber 43 in the forward throttle adjust- 'ing motor 38 to insure that piston 4I therein will occupy its steam cut-01f position to permit full closure of the supply valve 35 in the forward :throttle device 32 so as to prevent steam being supplied to the forward turbine. In other words, --provision has been made to insure against supply -of steam to the reverse turbine when the forward turbine is driving the locomotive, and to insure against supply of steam to the forward turbine when the reverse turbine is driving the locomoztive.

However, if a particle of hard foreign matter such as'pipe scale should become lodged on the seat of the poppet valve 35 or on the seating face cf said valve when open, in either the forward throttle valve 32 or reverse throttle valve 33, .such foreign matter might prevent closure of said valve and would therefore permit steam to leak to the respective turbine 9 or I2, when it is ;not desired. Such leakage to the reverse turbine is particularly objectionable for reasons hereinbefore described.

According to the invention an intercepting .lstructure IE8 is provided in the steam supply pipe I3 to the reverse turbine I2 for insuring that steam cannot be effective in said turbine in case ofileakage of steam past the poppet valve 35 in the reverse throttle valve 33 under conditions when said valve should be closed, as when the engine is stopped or being driven forwardly bythe reverse turbine I2.

The intercepting structure I68 (Fig. 6) comprises a casing having a chamber I69 connected to the portion of pipe I3 leading to chamber 35 in a reverse throttle valve 33, a chamber I18 connected to the portion of pipe I3 leading to the reverse turbine l2 and a chamber I1I which is open through a vent port I12 to atmosphere. In chamber I18 there are two oppositely seating poppet valves I13 and I14 which are arranged to;

move in unison. The valve I14 has a stem I15 loosely extending through an opening in a partition I16 separating chambers I38 and I18 and around said opening in chamber I is a seat provided for engagement by said valve. A spring ill in chamber I69 acts on the valve stem I for urging the valve I14 to the open position shown in the drawing. The valve I13 has an oppositely arranged fluted stem I18 extending .through an opening in a partition wall I19 into chamber I1I, said wall being provided in chamber I19 around said opening with a seat for said valve.

- In chamber I1I the valve stem I18 engages one side of a piston I80. At the opposite side of pis-vton I8!) is a chamber I8I which is connected to a pipe I82 leading to pipe 52 which is connected to spring chamber 43 in the reverse throttle adjusting motor 33. A spring IE3 in chamber I1I acts on piston i851 for urging it to the position in which it is shown in Fig. 6 of the drawing when chamber MI is open to atmosphere by way of pipes I82 and 52. Under this condition spring I11 will open valve I 14 and close valve I13. When fluid is supplied to chamber I 8I at a pressure 'sufiicient to overcome the pressure of spring I83 on piston I86 said piston will be moved to open valve I13 and close valve I14.

When the locomotive is stopped or operating in a forwardly direction, under which condition the reverse steam cut-off valve device 1| will be operated to supply fluid under pressure to pipe 52 and thence to spring chamber 43 in the reverse throttle adjusting motor 39 to insure movement of piston 4| therein to its steam cut-oil position, said fluid under pressure will also be efiective in chamber IBI of the intercepting structure I68 to close valve I14 and to open valve I13. The closing of valve I14 will, in case of leakage of steam past the poppet valve 35 in the reverse throttle valve 33, prevent such steam from becoming effective in the reverse turbine I2, while opening of valve I13 will permit such steam to be dissipated to atmosphere, whereby the rotor of the reverse turbine I2 will be permitted to remain stationary under such a condition.

The valve. I14 might be dispensed with if the venting capacity of valve I13 were sufficient to insuredissipation of steam leakage through the reverse throttle valve 33 to pipe I3 at a rate to prevent steam becoming effective in the reverse turbine I 2 at a pressure suflicient to cause operationof said turbine. Moreover the valve I13 mighteven be dispensed with since the possibility of both valve I14 and of valve 35 in the reverse throttle valve 33 being held open by foreign matter at the same time is extremely remote and the closing of either one would accomplish the desired end of preventing leakage of steam to the reverse turbine. However, applicant prefers to use both of the valves I13 and I14.

When the operators control valve device 55 is operated to cause movement of the locomotive by the reverse turbine I2 the reverse steam cut-off valvev device H is operated to release fluid under pressure from spring chamber 43 in the reverse throttle adjusting motor 39 as hereinbefore described, and at the same time fluid under pressure will be released from chamber IBI in the intercepting valve structure I68. Spring I11 will thereby be rendered effective to close valve I13 and open valve I14 for opening communication through the steam supply pipe I3 to the reverse turbine I2 whereby said turbine will operate in response to the operation of the operators control valve device, in the same manner as herein- ,before described.

Summary It will now be seen that by the use of the intercepting valve device $68 in the steam supply pipe I3 leading to the reverse turbine I2, supply of steam to said turbine when not desired, as in case of leakage past the poppet valve 35 in the reverse throttle valve 33, is positively prevented, so that the rotor of said turbine will remain stationary when the locomotive is stopped or is operating in a forward direction and thus prevent unnecessary and useless operation of said rotor and possible damage thereto or to the clutch 20, 2I or the reduction gear I6, such as above described.

It will be readily apparent that an interlock device identical to the interlock device I68 and arranged for control from pipe 5!] could be disposed in the steam supply pipe Ii] to the forward turbine 9 to insure against leakage of steam to said turbine in case the poppet valve 35 of the forward throttle valve 32 did not fully close when intended, if such were desired.

Having now described the invention, what I claim as new and desire to secure by Letters 17 steam supply valve means for supplying steam to and for cutting off the supply of steam to said pipe, other valve means for controlling communication through said pipe and for also dissipating steam leakage past said supply valve means, control means for eifecting operation of said supply Valve means to cut off the supply of steam to said pipe and for at the same time effecting operation of said other valve means to close said communication and to dissipate from said pipe steam leakage past said supply valve means, and for also effecting operation of said supply valve means to supply steam to said pipe and for at the same time efiecting operation of said other valve means to open said communication and to prevent dissipation of steam, and an operators control lever for controlling said control means.

2. A control apparatus for a steam turbine comprising, steam supply valve means for supplying steam to and for cutting oil the supply of steam to said turbine, a fluid motor comprising power means for controlling said valve means and operable upon supply of fluid under pressure to one chamber when fluid under pressure is released from a second chamber to effect operation of said valve means to supply steam to said turbine and operable upon supply of fluid under pressure to said second. chamber when fluid under pressure is released from said one chamber to effect operation of said valve means to cut off supply of steam to said turbine, control means for selectively supplying fluid under pressure to either one of said chambers and for at the same time releasing fluid under pressure from the other chamber, intercepting means operable by fluid under pressure in a third chamber for preventing steam leaking past said supply valve means becoming eifective in said turbine, said intercepting means being rendered ineffective upon release of fluid under pressure from said third chamber, and means connecting said third chamber to said second chamber for rendering said intercepting means operable in accordance with the pressure of fluid in said second chamber.

3. A control apparatus for a steam turbine comprising a steam supply pipe for said turbine, steam supply valve means for supplying steam to and for cutting off the supply of steam to said pipe, a fluid motor comprising power means for controlling said supply valve means and operable upon supply of fluid under pressure to one chamber when fluid under pressure is released from a second chamber to effect operation of said supply valve means to supply steam to said pipe and operable upon supply of fluid under pressure to said second chamber when fluid under pressure is released from said one chamber to effect operation of said valve means to cut off supply of steam to said pipe, control means for selectively supplying fluid under pressure to either one of said chambers and for at the same time releasing fluid under pressure from the other chamber, a vent for releasing fluid under pressure from said pipe, a vent valve for opening and closing said vent, power means subject to pressure of fluid in said second chamber and operable upon supply of fluid under pressure thereto to effect operation of said vent valve to open said vent, and means operable upon release of fluid under pressure from said second chamber to eifect operation of said vent valve to close said vent.

4. A control apparatus for a steam turbine comprising a steam supply pipe for said turbine, steam supply valve means for supplying steam to and for cutting off the supply of steam to said pipe, a fluid motor comprising power means for controlling said supply valve means and operable upon supply of fluid under pressure to one chamber when fluid under pressure is released from a second chamber to effect operation of said supply valve means to supply steam to said pipe and operable upon supply of fluid under pressure to said second chamber when fluid under pressure is released from said one chamber to effect operation of said valve means to out 01f supply of steam to said pipe, control means for selectively supplying fluid under pressure to either one of said chambers and for at the same time releasing fluid under pressure from the other chamber, a valve for controlling communication through said pipe, power means operable by fluid under pressure to actuate said valve to close said communication, means operable upon release of fluid under pressure on said power means to actuate said valve to open said communication, and means subjecting said power means to pressure of fluid in said second chamberj 5. A control apparatus for a steam turbine comprising a steam supply pipe for said turbine, steam supply valve means for supplying steam to and for cutting ofl the supply of steam to said pipe, a fluid motor comprising power means for controlling said supply valve means and operable upon supply of fluid under pressure to one chamber when fluid under pressure is released from a second chamber to effect operation of said supply valve means to supply steam to said pipe and operable upon supply of fluid under pressure to said second chamber when fluid under pressure is released from said one chamber to effect operation of said valve means to cut off supply of steam to said pipe, control means for selectively supplying fluid under pressure to either one of said chambers and for at the same time releasing fluid under pressure from the other chamber, intercepting valve means controlling communication through said pipe and controlling a vent from said pipe for dissipating from said pipe steam leakage past said supply valve means, power means for controlling said intercepting valve means and operable by fluid under pressure to effect operation of said intercepting valve means to close said communication and to open said vent, means operable upon release of fluid under pressure from said power means to effect operation of said intercepting valve means to open said communication and to close said vent, and means subjecting said power means to pressure of fluid in said second chamber.

ELLIS E. HEWITT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 741,261 Ledermann Oct. 31, 1903 1,521,724 Sour Jan. 6, 1925 1,690,093 Allen Nov. 6, 1928 1,931,104 Caughey Oct. 1'7, 1933 2,294,753 Hedman Sept. 1, 1942 

